1. Field of the Invention
This invention relates to the field of power supplies, and particularly to fault tolerant cooling in a redundant power system.
2. Description of the Related Art
A power system that provides power to an electronic device often includes multiple power supplies in parallel. This type of redundant power system provides for uninterrupted power generation even if one or more of the power supplies fail or cease to fully function. The multiple power supplies typically power a common bus which powers an electronic load for the components of the electronic device.
The internal components of a power supply and the components of an electronic device that receives power from a power system can generate a great deal of heat. Without appropriate cooling, these components can overheat and fail. Fans are commonly used in power supplies to provide cooling and are often integrated into and powered by the power supply in which the fans reside.
However, because the integrated fan is powered by the power supply, if the power supply fails or becomes non-functioning, the fan, which is still functional, will also stop running because the fan loses its power source. As a result, the components in the electronic device will run hotter than normal temperature due to the absence of a working fan. In addition, in a redundant power system with multiple power supplies, if a power supply fails, the overall efficiency of the entire cooling system may also suffer. This is often due to air blown by the fans from the other functioning power supplies traveling back through the non-functioning power supply instead of travelling through the electronic device. Without the air pressure caused by air being pushed through the non-functioning power supply by a fan, the non-functioning power supply may become the path of least resistance for air travel, thus decreasing the effectiveness of the functioning fans.